changeable

Synonyms: agitated capricious changeful commutative convertible fickle fitful flighty fluctuating fluid impulsive inconstant indecisive irregular irresolute irresponsible kaleidoscopic mercurial mobile movable mutable permutable protean restless reversible revocable shifting skittish spasmodic transformable transitional uncertain unpredictable unreliable unsettled unstable unsteady vacillating vagrant variable variant varying versatile volatile wavering whimsical

Antonyms: certain changeless constant fixed lasting reliable stable steady sure unchangeable undeviating